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moayed--mojtaba
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Development and Application of a Model for Assessment of Energy Sector in Middle East and the Role of Iran
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
The Middle-East with its enormous fossil fuel resources is considered as one of the most important regions with regard to the future world energy outlook. The region produced more than 32% and 16% of the world oil and gas, respectively, in 2012 and contains more than 48% of proven oil and 43% of proven gas reserves in the world and with 78 years of reserves-to-production ratio (RPR or R/P) has a key role in global energy provision. However, the energy issues in the region are intensifying. For instance, the fossil resources are pushed to the second half of their life time due to massive exploitation which results in change in production processes and raises the need for energy investment, on...
A sensitive and selective colorimetric method for detection of copper ions based on anti-aggregation of unmodified gold nanoparticles
, Article Talanta ; Vol. 129, issue , 2014 , pp. 227-232 ; ISSN: 00399140 ; Abbasi-Moayed, S ; Sharif University of Technology
2014
Abstract
A highly sensitive and selective colorimetric method for detection of copper ions, based on anti-aggregation of D-penicillamine (D-PC) induced aggregated gold nanoparticles (AuNPs) was developed. Copper ions can hinder the aggregation of AuNPs induced by D-PC, through formation of mixed-valence complex with D-PC that is a selective copper chelator. In the presence of a fixed amount of D-PC, the aggregation of AuNPs decreases with increasing concentrations of Cu2+ along with a color change from blue to red in AuNPs solution and an increase in the absorption ratio (A520/A 650). Under the optimum experimental conditions (pH 7, [AuNPs] =3.0 nmol L-1 and [NaCl]=25 mmol L-1), a linear calibration...
A Visual Colorimetric Probe for Naked-Eye Detection of Pamidronate Disodium in Human Plasma Based on Aggregation of Citrate-Capped Gold Nanoparticles
, Article Plasmonics ; Volume 10, Issue 4 , 2015 , Pages 971-978 ; 15571955 (ISSN) ; Abbasi-Moayed, S ; Sharif University of Technology
Springer New York LLC
2015
Abstract
Herein, a sensitive, simple, and rapid colorimetric assay for the detection of pamidronate disodium was developed based on the aggregation of citrate-capped gold nanoparticles (AuNPs). This was exploited from the affinity of electron-rich atoms toward the surface of AuNPs, resulting in the aggregation of AuNPs through intermolecular hydrogen bonding interactions. As a result of aggregation under optimum conditions ([NaCl] = 25 mM, [AuNPs] = 3.3 nM and pH 7.0), the color of AuNPs was changed from red to blue and the plasmon band of AuNPs around 520 was decreased along with the formation of a new peak at a longer wavelength in the approximate range of 600 to 700 nm. The intensity ratios of...
A multichannel single-well sensor array for rapid and visual discrimination of catecholamine neurotransmitters
, Article Sensors and Actuators, B: Chemical ; Volume 296 , 2019 ; 09254005 (ISSN) ; Hormozi Nezhad, M. R ; Maaza, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, for rapid identification and discrimination of catecholamine neurotransmitters in the presence of ascorbic acid (AA), a tricolor fluorescence probe has been constructed by integrating three recognition elements including blue carbon dots (bCDs), green CdTe quantum dots (gQDs) and red CdTe quantum dots (rQDs) into a single well. The proposed array exhibited ternary fluorescence emissions at 450, 520 and 630 nm with an overall luminescent pink emission under a single wavelength excitation (365 nm). In order to produce distinct response patterns from a single fluorimetric test, the spectral changes and the corresponding color variations of the multichannel fluorescence probe were...
Corrigendum to “ththnated development of a pH assisted AgNP-based colorimetric sensor array for simultaneous identification of phosalone and azinphosmethyl pesticides” [spectrochim. acta a mol. biomol. spectrosc. 219 (2019) 496–503](S138614251930455X)(10.1016/j.saa.2019.04.074)
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 223 , 2019 ; 13861425 (ISSN) ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The authors regret “There are some meaningless letters at the beginning of the article's title. The authors would like to inform that the correct title is “Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides.” The authors would like to apologise for any inconvenience caused. © 2019 Elsevier B.V
ThThnated Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 219 , 2019 , Pages 496-503 ; 13861425 (ISSN) ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand. Herein, we have introduced a silver nanoparticle (AgNP)based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM)and Phosalone (PS)pesticides. In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5)showed different aggregation behaviors. As a result of aggregation, the color and UV–Vis spectra of AgNPs changed differentially, leading to distinct response patterns for AM and PS. The aggregation induced spectral changes of AgNPs, were used to identify AM and PS...
Application of NaYF4:Yb/Er/Tm UCNPs in Array-Based Sensing of Neurotransmitters: From a Single Particle to a Multichannel Sensor Array
, Article ACS Applied Materials and Interfaces ; 2020 ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
American Chemical Society
2020
Abstract
A novel multichannel sensor array has been designed using a single, yet multiemissive lanthanide-doped upconversion nanoparticle (UCNP). The energy levels of lanthanide ions gave rise to several emission bands which were exploited as individual sensor elements for the recognition of four important neurotransmitters (NTs): dopamine, norepinephrine, levodopa, and serotonin. At alkaline conditions, the oxidation products of these NTs quenched the fluorescence emissions of UCNPs with different quenching degrees. The resulting fingerprint multichannel emission profiles from NaYF4:Yb/Er/Tm UCNPs allowed the discrimination of NTs with excellent accuracy. The recognition was further verified in...
A nanopaper-based artificial tongue: a ratiometric fluorescent sensor array on bacterial nanocellulose for chemical discrimination applications
, Article Nanoscale ; Volume 10, Issue 5 , February , 2018 , Pages 2492-2502 ; 20403364 (ISSN) ; Golmohammadi, H ; Hormozi Nezhad, M. R ; Sharif University of Technology
Royal Society of Chemistry
2018
Abstract
In the present study, a ratiometric fluorescent sensor array as an artificial tongue has been developed on a nanopaper platform for chemical discrimination applications. The bacterial cellulose (BC) nanopaper was utilized for the first time as a novel, flexible, and transparent substrate in the optical sensor arrays for developing high-performance artificial tongues. To fabricate this platform, the hydrophobic walls on the BC nanopaper substrates were successfully created using a laser printing technology. In addition, we have used the interesting photoluminescence (PL) properties of an immobilized ratiometric probe (carbon dot-Rhodamine B (CD-RhB) nanohybrids) on the nanopaper platform to...
Determination of spermine and spermidine in meat with a ratiometric fluorescence nanoprobe and a combinational logic gate
, Article Food Chemistry ; Volume 384 , 2022 ; 03088146 (ISSN) ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
A ratiometric fluorescent nanoprobe is developed with a wide color variation for visual determination of spermine (SP) and spermidine (SD) in meat samples. The green emission provided from the combination of yellow emissive quantum dots and blue emissive carbon dots turns into pink when SP or SD are present. The results show that the developed sensor has good linearity in the range of 0.5–10 and 0.5–80 µM for SP and SD and suitable detection limits were achieved including 0.2 and 2.1 µM for SP and SD. The probe was highly selective in the presence of amino acids and other biogenic amines. RGB indices were extracted to build a combinational logic gate for visual and simultaneous detection of...
Multiplex Detection of Biogenic Amines for Meat Freshness Monitoring Using Nanoplasmonic Colorimetric Sensor Array
, Article Biosensors ; Volume 13, Issue 8 , 2023 ; 20796374 (ISSN) ; Orouji, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
Multidisciplinary Digital Publishing Institute (MDPI)
2023
Abstract
Biogenic amines (BAs) were presented as significant markers for the evaluation of the spoilage of meat and meat products. In this work, a colorimetric sensor array was developed for the discrimination and detection of spermine (SP), spermidine (SD), histamine (HS), and tryptamine (TP) as important BAs in food assessment. For this aim, two important spherical plasmonic nanoparticles, namely gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs), were utilized as the sensing elements of the probes. The cross-reactive interaction of the target biogenic amines and the plasmonic nanoparticles caused the aggregation-induced UV–Vis spectra changes, which were accompanied by visual color...
Spectrophotometric Determination of Copper Ions and Pamidronate Disodium Based on Changing the Surface Plasmon Resonance Band of Au Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
Abstract
In recent years, metallic nanoparticles, specially gold and silver nanoparticles, have received great attention for biological and metal ions analysis, due to the surface plasmon resonance phenomena. Gold nanoparticles (AuNPs) have recently gained much interest in colorimetric probe based on aggregation or anti-aggregation of AuNPs, due to their simplicity and having high order of magnitude extinction coefficients, in addition to the dependence of surface plasmon resonance wavelength and intensity on the interparticles distances. In the first part of this thesis, a highly sensitive colorimetric method for detection of copper ions based on anti-aggregation of citrate capped AuNPs was...
Pulsed-laser annealing of NiTi shape memory alloy thin film
, Article Journal of Materials Science and Technology ; Volume 25, Issue 1 , 2009 , Pages 135-140 ; 10050302 (ISSN) ; Rezvani, E ; Sanjabi, S ; Ziaei Moayed, A. A ; Sharif University of Technology
2009
Abstract
Local annealing of amorphous NiTi thin films was performed by using an Nd:YAG 1064 nm wavelength pulsed laser beam. Raw samples produced by simultaneous sputter deposition from elemental Ni and Ti targets onto unheated Si (100) and Silica (111) substrates were used for annealing. Delicate treatment with 15.92 W/mm2 power density resulted in crystallization of small spots; while 16.52 and 17.51 W/mm2 power densities caused ablation of the amorphous layer. Optical microscopy, scanning electron microscopy, X-ray diffraction and atomic force microscopy were performed to characterize the microstructure and surface morphology of the amorphous/crystallized spot patterns
A rainbow ratiometric fluorescent sensor array on bacterial nanocellulose for visual discrimination of biothiols
, Article Analyst ; Volume 143, Issue 14 , 2018 , Pages 3415-3424 ; 00032654 (ISSN) ; Golmohammadi, H ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
Royal Society of Chemistry
2018
Abstract
Considering the crucial role of biothiols in many biological processes, which turns them into highly valuable biomarkers for the early diagnosis of various diseases, the development of an affordable, sensitive and portable probe for the identification and discrimination of these compounds is of great importance. Herein, we developed a ratiometric fluorescent (RF) sensor array with a wide color emissive variation, on a bacterial cellulose (BC) nanopaper substrate for the visual discrimination of biothiols. To this aim, RF sensing elements including N-acetyl l-cysteine capped green CdTe quantum dots-rhodamine B (GQDs-RhB) and red CdTe QDs-carbon dots (RQDs-CDs) at two different NaOH...
A wide-range pH indicator based on colorimetric patterns of gold@silver nanorods
, Article Sensors and Actuators B: Chemical ; Volume 358 , 2022 ; 09254005 (ISSN) ; Abbasi Moayed, S ; Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The potential of hydrogen (pH) is a basic and critical parameter representing the function of numerous chemicals/biomolecules. Due to the widespread applications of pH in diverse fields, the development of rapid and simple yet reliable probes for the determination of pH has attracted significant interest. In this paper, by using AuNRs, silver ions, and ascorbic acid as colorimetric pH sensor, a multicolorimetric nanosensor is described for pH measurement. The reduction of silver ions by ascorbic acid which is strongly influenced by pH, results in silver nanoshell deposition on the surface of AuNRs. Consequently, the formation of Au@Ag core-shell NRs causes a series of blue shifts in the...
Preparation, Surface Modification and Application of Nanocomposite Membranes Based on Transition Metals- Dichalcogenide Nanoparticles in Forward Osmosis Desalination Process
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor) ; Ahadian, Mohammad Mahdi (Supervisor) ; Amini, Mojtaba (Supervisor)
Abstract
Different parts of this research are focused on developing FO membranes and improving their performance. For this purpose, thin film composite (TFC) membranes with fixed composition of polyethersulfone/polyamide (PES/PA) have been used to investigate the effect of nanocomposites containing transition metal dichalcogenides (TMDs) on their performance. The support layer in all cases is PES, which is prepared through the phase inversion process and does not contain any nanofillers. The modification process takes place in the polyamide layer by dispersing the desired nanoparticles in the aqueous monomer solution necessary to form this active layer. Identification and characterization of...
Synthesis, Structure and Catalytic Application of Mn, Fe and Mo Complexes with Schiff base and Oxazoline ligands and Theoretical Mechanistic Studies on the Role of Heme and non-Heme Iron(IV)-Oxo Species in Hydroxylation and Epoxidation Reactions
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
The first part of this thesis describes the synthesis and characterization of several Mn, Fe and Mo complexes containing tridentate Schiff base and oxazoline ligands and their reactivities as catalysts in the oxidation of organic compounds like olefins and sulfides, as well. The crystal structures of newly prepared cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO2(phox)2] and (N-hydroxyphenyl-salicylidenamine)(acetylacetonato)ethanol iron(III), [FeIII(N-OPh-sal)(acac)EtOH] complexes have been described by X-ray crystallography. Due to the difficulties in the preparation of suitable single crystals of novel...
Design and Fabrication of RFID Front END Transceiver single chip with 2.5W Output Power
, Ph.D. Dissertation Sharif University of Technology ; Atarodi, Mojtaba (Supervisor)
Abstract
This thesis deals with the front-End of an Integrated RFID Reader operated in 860MHz to 960MHz, which integrates a RF transceiver including PA, LNA and Mixer. In the receiver part, a power amplifier was fabricated and measured and in the transmitter part, LNA and Mixer were designed. There is a growing interest in utilizing CMOS technologies for RF power amplifiers (PAs). Although several advances have been made recently to enable full integration of PAs in CMOS, it is still among the most difficult challenges in achieving a truly single-chip radio system in CMOS. This is exacerbated by supply voltage reduction due to CMOS technology scaling and on-chip passive losses due to the conductive...
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
Inert gold become catalytically active when dispersed in the form of nanoparticles. Isolated gold nanoparticles have demonstrated high catalytic activity for both oxidation and reduction reactions. In order to obtain high catalytic activity, gold nanoparticles are generally dispersed on support materials, among which oxides are commonly used. However, a substantial decrease in activity and selectivity of the immobilized catalysts is frequently observed due to the heterogeneous nature of these support materials in reaction media. In the course of our study on the metal-based catalysis for synthesis of organic compounds, we herein report that rod-shaped Au nanoparticles in aqua solution...
Synthesis and Characterization of a novel Ruthenium(II) Complex With Bidentate O,N-donor OxazolineLigand and Study of Catalytic Oxidation of Sulfides and Alkanes
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
The 2-(2′-hydroxyphenyl)-oxazoline ligand (Hphox) is generated from 1:1 condensation of methyl salicylate with 2-aminoethanol. Novel [Ru(Hphox)2(H2O)2] (Hphox = 2-(2′-hydroxyphenyl)-oxazoline ) complex has been synthesized and characterized by physic-chemical methods. Oxidation of sulfides catalyzed by the mixed-ligand ruthenium(II) complex [Ru(Hphox)2(H2O)2]using urea-hydrogen peroxide (UHP) as oxidant was investigated under mild condition within 1 h. The results showed that mixed-ligand ruthenium(II) complex was effective catalyst in oxidation of sulfides in whichsulfoxideswere the only products. Using this catalytic system in the oxidation of alkanes, ketones were obtained as the main...
Synthesis of Core-Shell Nanoparticles Supported Iron and Vanadium Schiff Base and Their Application as a Catalyst for Oxidation of Sulfides, Alcohols and Olefins
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this work, synthesized Fe3O4 magnetic nanoparticles andcoated with SiO2 to prepare magnetic core-shell nanoparticles. Then immobilized Schiff baseof iron and vanadium complexes on magnetic core-shell nanoparticles was prepared as a recoverable magnetic nano catalysts. These catalysts were named Fe3O4@SiO2@L1@Fe, Fe3O4@SiO2@L2@Fe and Fe3O4@SiO2@L3@V. Furthermore,olefines epoxidation, sulfides and alcohols oxidation were studied with using iron and vanadium magnetic nano catalysts. The supported catalysts were characterized by atomic absorption, FT-IR and UV–Vis spectra.The catalytic performance of the synthesized iron catalyst was tested for the epoxidation of cyclohexene, styrene and...